Are California's storms normal, or is climate change making them worse? What experts say.

California faces a "parade of storms" over the next several weeks, on top of deluges that have killed at least 12 people, caused flooding, knocked out power and forced evacuations and school closures up and down the coast.

Given the Mediterranean climate of the state's coastal areas, wet winters and dry summers are a natural part of California's weather patterns going back millennia.

But are this year's storms something out of the ordinary, and something that can be attributed to climate change? In a state that is home to almost 40 million people with a $3.6 trillion economy – on track to be the fourth-biggest in the world – the weather matters.